Touch-sensitive surfaces are rapidly becoming more common in computing devices. They are very convenient as they allow a user to make natural gestures familiar to the user in other contexts, such as by entering handwriting using a special stylus such as an elongated pen-like object having a pointed tip. The term touch-sensitive surface or device will be used herein to refer to such surfaces or devices, such as digitizers that may be separate from or integral with a display, that are configured to detect the touch of a stylus. The term “stylus” as used throughout herein includes any type of stylus such as a specially-designed stylus device (e.g., a pen) or even a user's finger. Various touch-sensitive surfaces provide for a hover function, meaning that the touch-sensitive surface is capable of detecting the presence of the stylus without the stylus actually touching the touch-sensitive surface. For example, some touch-sensitive devices can detect the presence of a stylus within approximately 2 centimeters of their touch-sensitive surfaces. This is referred to as hovering with the stylus. This capability may allow the user to position the cursor over an area prior to taking an action such as generating a left mouse button down command, also known as a left click. Hovering with a stylus is similar to moving the cursor using a mouse, and pressing down with the stylus (e.g., by tapping the stylus on the surface of the touch-sensitive device) is similar to pressing the left or right buttons of the mouse.
However, precise targeting using a stylus and touch-sensitive surface can sometimes be difficult, especially where accuracy is important. For example, if a user desires to tap a stylus on a particular point of a touch-sensitive display device, the user may receive feedback in the form of a displayed cursor that follows the movements of the stylus while it is hovering and prior to the tap. This allows the user to see where the intended tap location will be. However, as the stylus approaches the touch-sensitive device and eventually comes into contact with it, the actual tap location may differ from the intended location. Small targets, parallax, poor digitizer quality, and shaky hands can contribute to such targeting difficulties.
Accordingly, there is a need for ways to overcome, counteract, or minimize such targeting difficulties.